This invention relates to the operation and safety of water-cooled nuclear reactors, and in particular to methods for minimizing the dangers of exposure of workers to radioactive emissions during reactor shutdown.
A major hazard in water-cooled nuclear reactors is the accumulation of radioactive substances in the structural portions of the reactor. During reactor shutdown, workers are exposed to stainless steel internal walls and piping surfaces, and radioactive materials retained in oxide films which have accumulated on these surfaces are a major source of radiation exposure.
The introduction of certain metallic ions, including zinc, has been used to remove or lessen such deposition. Zinc however is itself a source of radioactivity in these reactors, and this radioactivity limits the effectiveness of the use of zinc.